The invention relates to a sealing profile for sealing a casing with respect to a cover disk of a lamp. The lamp casing has a groove with a groove base for receiving the sealing profile.
In the case of a known sealing profile of this type (DE 298 10 708 U1, FIG. 2) greater protection against moisture seeping in at the bottom of the groove is already achieved by a sealing rib at the foot section.
DE 42 05 442 A1 discloses the placement of a planar base surface of a sealing profile with its entire surface against a complementary planar base surface in the base of a receiving groove. This arrangement is still not able to prevent moisture from seeping in.
The object of the invention is to prevent in a reliable manner moisture seeping in at the base of the lamp casing groove.
This object is achieved by virtue of a sealing profile extruded from at least one elastomer. The sealing profile comprises a seal section with lateral contact surfaces and a top contact surface which interacts with the cover disk. A connection section is attached to the seal section and has a reduced cross sectional surface relative to the seal section. A foot section is attached to the connection section, the foot section being provided with lateral retaining lips. The foot section comprises a strip which interacts in a sealing manner with the groove base. The strip prevents any penetration of moisture between the sealing profile and the base of the groove. A preferred area of application is the sealing of motor vehicle headlamps, where the cover disk can be made from synthetic material or glass and where it is imperative that the sealing effect is always guaranteed even during changes in temperature and vibrations.
Preferably, a retaining groove is positioned in the foot section of the sealing profile. The strip is held in the retaining groove in a reliable manner even when the sealing profile is in the relaxed state.
In order to guarantee the adhesive characteristics of the strip even until the sealing profile is inserted into the groove, the strip is covered by a cover sheet positioned along a surface region protruding out of the retaining groove.
Alternately, the strip may be disposed entirely within the retaining groove of the foot section when the sealing profile is in a relaxed state and not yet inserted into the lamp casing groove. The strip can be protected in this manner even without a cover sheet until it is inserted in the lamp casing groove.
This protective effect may be further enhanced by positioning the strip at a spaced disposition from an outer contour of the relaxed foot section.
The retaining groove is defined by inner ends of the retaining lips, thus, during the process of inserting the sealing profile into the groove the cross-sectional shape of the retaining groove can be changed in a convenient manner as desired.
When the sealing profile is in the relaxed state the lip inner ends form a gap between themselves. This facilitates the process of pressing the strip out of the retaining groove.
When inserting the sealing profile into the lamp casing groove the retaining lips can be pivoted towards and pressed against the lateral surfaces of the connection section. Thus it is possible to control in an extremely precise manner the process of pressing out the strip and to influence said process.
In order to promote the pressing-out effect each lateral surface is provided with a rib which protrudes outwards towards the associated retaining lip. This enhances the pressing-out effect, wherein the mass of the strip can spread out in the desired manner and to the desired extent between the groove base and the inserted sealing profile and a sufficiently permanent sealing effect can be ensured.
When the sealing profile is inserted into the groove the strip is disposed with a portion of its cross-sectional surface in the retaining groove of the foot section. Thus the strip is held in a particularly reliable manner in situ in the foot section.
The strip preferably comprises a permanently elastic permanently adhering sealing mass which may be made of, for example, a butyl-based elastomer. These features ensure a permanent, complete moisture seal at the base of the groove.
Making the sealing profile from an EPDM cellular rubber having a Shore A hardness of 15-25 provides a particularly favourable sealing effect on the one hand within the groove and on the other hand between the seal section and the cover disk.